An Ancient Era of Global Warming Could Hint at Our Scorching Future

Looking back at the strange and sweaty days of the PETM.

An ancient warming event may have lasted longer than we thought

Fifty-six million years ago, during the Paleocene-Eocene Thermal Maximum (PETM), global temperatures rose by more than 5°C over 100,000 or more years. Between 3,000 and 20,000 petagrams of carbon were released into the atmosphere during this time, severely disrupting ecosystems and ocean life globally and creating a prolonged hothouse state.

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Overstromingen Spanje waren echo van klimaatverandering in prehistorie

Valencia werd in oktober totaal verrast door de overstromingen die meer dan tweehonderd mensen het leven kostten. Maar diep onder de grond werd jaren geleden al bewijs gevonden dat dit zou kunnen gebeuren, zegt hoogleraar Appy Sluijs in een eindejaarsinterview met NU.nl.

Nonparametric estimation of age-depth models from sedimentological and stratigraphic information

Abstract. Age-depth models are fundamental tools used in all geohistorical disciplines. They assign stratigraphic positions to ages (e.g., in drill cores or outcrops), which is necessary to estimate rates of past environmental change and establish timing of events in sedimentary sequences. Methods to estimate age-depth models commonly use simplified parametric assumptions on the uncertainties of ages of tie points. The distribution of time between tie points is estimated using simplistic assumptions on the formation of the stratigraphic record, for example that sediment accumulates in discrete events that follow a Poisson process. In general, age-depth models are a crude simplification that fail to provide a comprehensive implementation of all empirical data or expert knowledge (e.g., from sedimentary structures such as erosional surfaces or from basin models). In other words, many information sources that can potentially provide geochronologic information remain un- or underused. Here, we present two non-parametric methods to estimate age-depth models from complex sedimentological and stratigraphic data. The methods are complementary as they use different sources of information (sedimentation rates and observed tracer values), are implemented in the admtools package for R Software and allow the user to specify any error model and distribution of uncertainties. As use cases of the methods, we construct age-depth models for the Late Devonian Steinbruch Schmidt section in Germany and use it to estimate the timing of the Frasnian-Famennian boundary and the duration of the Upper Kellwasser event. use measurements of extra-terrestrial 3He from ODP site 960 (Maud Rise, Weddell Sea) to construct age-depth models for the Paleocene–Eocene thermal maximum (PETM). The first case study suggests that the Upper Kellwasser event lasted 89 kyr (IQR: 84 to 97 kyr) and places the Frasnian-Famennian boundary at 371.834 ± 0.101 Ma (2 σ), whereas the second case study provides a duration of 41 to 48 kyr for the PETM recovery interval. These examples show how information from a variety of sedimentological and stratigraphic sources can be combined to estimate age-depth relationships that accurately reflect uncertainties of both available data and expert knowledge.

Earth's Orbit Mysteriously Altered by Chance Encounter Million of Years Ago

A grazing encounter between the Solar System and a passing star could once have changed Earth's orbit enough to wreak havoc on the climate, new research has found.